Device and method for simulating positive pressure ventilation of biological lung of human body

Abstract

The invention discloses a human body biological lung positive pressure ventilation simulation device and method.The device comprises a biological simulation lung, a three-way connector, an air pressure throttling pipe, an air blower, a vacuum pump, a pressure sensor, a controller and an upper computer, and three connectors of the three-way connector are connected with the biological simulation lung, the air pressure throttling pipe and an air extraction opening of the vacuum pump respectively; an air outlet of the air blower is connected with the air pressure throttling pipe, a plurality of throttling holes are formed in the air pressure throttling pipe and located in the same circumferential face, two detection pipes are led out of the air pressure throttling pipe, air inlets of the two detection pipes are located in the upstream side and the downstream side of the throttling holes, and a pressure sensor is arranged at an air outlet of each detection pipe. The pressure sensor is connected with the controller, and the controller is connected with the upper computer.

Description

Technical Field

[0001] The invention relates to a positive pressure ventilation device and method for simulating human biological lungs. Background Art

[0002] Due to the rapid development of pulmonary interventional treatment solutions, various advanced pulmonary interventional treatment devices, consumables and other equipment have emerged in an endless stream. This also makes it difficult for attending physicians to quickly master the use of relevant new pulmonary interventional treatment medical devices and consumables. At present, most doctors use live animal experiments to master the use of pulmonary interventional medical devices and related consumables. During the pulmonary intervention animal experiment, doctors will perform experiments such as lung puncture, lung tissue biopsy, and lung tissue radiofrequency ablation on animals. On the one hand, these experiments will cause harm and death to animals. On the other hand, due to the limited number of animals raised specifically for medical experiments, it is impossible for doctors to have a large-scale experimental environment where they can practice and use new pulmonary interventional medical devices and related consumables. Therefore, in order to overcome these drawbacks, some domestic medical device companies for pulmonary interventional treatment have developed a biological simulation lung experimental platform.

[0003] The general mechanical ventilation mode is a commonly used life-saving treatment method. Usually, the mechanical ventilation mode is divided into positive pressure ventilation mode and negative pressure ventilation mode. Due to the particularity of the biological simulated lung, it is impossible to actively exhale gas. Therefore, most medical device companies that develop this experimental platform for pulmonary interventional treatment basically use negative pressure ventilation mode to simulate human lung breathing. However, the air pressure waveform curve obtained by the simulation effect under this mode is far from the real human lung breathing air pressure curve. Therefore, it is of great significance to invent a positive pressure ventilation device for biological simulated lungs to provide a realistic experimental environment for medical devices for pulmonary interventional treatment. Summary of the invention

[0004] The present invention aims to solve the problems existing in the prior art and provides a positive pressure ventilation device and method for simulating human biological lungs.

[0005] The technical solutions adopted in the present invention are:

[0006] A positive pressure ventilation device simulating human biological lungs comprises a biological simulated lung, a three-way joint, an air pressure throttling tube, a blower, a vacuum pump, a pressure sensor, a controller and a host computer, wherein three interfaces of the three-way joint are respectively connected to the biological simulated lung, the air pressure throttling tube and the air suction port of the vacuum pump, the air outlet of the blower is connected to the air pressure throttling tube, a plurality of throttling holes are arranged in the air pressure throttling tube, all the throttling holes are located on the same circumferential surface, two detection tubes are led out of the air pressure throttling tube, the air inlets of the two detection tubes are located on both sides of the upstream and downstream of the throttling holes, a pressure sensor is arranged at the air outlet of each detection tube, the pressure sensor is connected to the controller, and the controller is connected to the host computer.

[0007] Furthermore, a disposable tracheal cannula is inserted into the biological simulated lung, and the tracheal cannula is connected to a three-way connector.

[0008] Furthermore, two bellows are connected to the three-way joint, and the two bellows are respectively connected to the air pressure throttling tube and the vacuum pump.

[0009] Furthermore, the air pressure throttle tube is a detachable structure, including a connecting tube and a throttle tube, a throttle plate is provided in the inner cavity of the throttle tube, the throttle plate and the throttle tube are integrally formed, and the throttle plate is provided with a plurality of throttle holes; two connecting tubes are threadedly connected to both sides of the throttle tube, and each connecting tube is provided with a connector for connecting to the detection tube.

[0010] The present invention also discloses a method for simulating positive pressure ventilation of human biological lungs. The air pressure value and air flow rate value are preset in the host computer. Under the set ventilation mode, the blower and the vacuum pump are set to open and close alternately to realize the simulated breathing of the biological simulated lung. The end of each working time of the vacuum pump is a simulated breathing cycle of the biological simulated lung.

[0011] Further, the ventilation mode includes a controlled air pressure positive pressure ventilation mode, and the controlled air pressure positive pressure ventilation mode is:

[0012] The actual air pressure value of the air pressure throttle tube is collected in real time through the pressure sensor on the detection tube downstream of the throttle hole, and the actual air pressure value is transmitted to the controller. The air pressure value preset on the host computer is transmitted to the controller. The actual air pressure value and the preset air pressure value form an incremental control signal through the incremental PID control algorithm in the controller. The incremental control signal is sent to the drive board connected to the blower. The blower speed is adjusted by the blower drive board until the actual air pressure value collected in real time is equal to the preset air pressure value. When the actual air pressure value is equal to the preset air pressure value, the vacuum pump starts working. When the vacuum pump reaches the set working time, it is a simulated breathing cycle. The blower starts the next simulated breathing cycle by controlling the air pressure positive pressure ventilation mode again.

[0013] Furthermore, the ventilation mode also includes an adaptive pressure-regulated volume positive pressure ventilation mode, and the adaptive pressure-regulated volume positive pressure ventilation mode is:

[0014] The actual air pressure difference formed by the air flow passing through the throttle hole is collected by the pressure sensor on the upstream and downstream detection tubes of the throttle hole, and the air pressure difference is converted into an actual airflow value through the fuzzy PID control algorithm in the controller. The actual airflow value is compared with the preset airflow value in the host computer. If the actual airflow value is not equal to the preset airflow value, the speed of the blower is increased or decreased in the next simulated breathing cycle, and then the air pressure value is increased or decreased, thereby forming an adaptive feedback control ventilation mechanism. The opening and closing of the vacuum pump in each simulated breathing cycle is achieved by setting the opening and closing time frequency of the vacuum pump.

[0015] Furthermore, the pressure difference is converted into an actual airflow value, and the specific function is:

[0016]

[0017] In the formula, β 2 is the diameter ratio of the air pressure throttle tube;

[0018] β 2 =A2 / A1, A2 is the opening area of ​​the throttle hole, A1 is the cross-sectional area of ​​the throttle pressure throttle pipe;

[0019] d is the opening diameter of the throttle hole; ρ is the air density; ε is the expansion coefficient, which is 1 here;

[0020] Δp is the actual pressure difference formed by the airflow passing through the throttle hole;

[0021] The relationship formula between the actual pressure difference and airflow rate formed by the airflow passing through the throttle hole is:

[0022]

[0023] Wherein, C=137.4.

[0024] Furthermore, the host computer displays a waveform of the actual air pressure value in real time.

[0025] Furthermore, the air pressure value for increasing or decreasing ▲P is calculated by the following formula:

[0026]

[0027] The present invention has the following beneficial effects:

[0028] The present invention takes into account the physiological and physical characteristics of human breathing and has a high degree of bionic characteristics. It can also adjust breathing-related parameters online and simulate multiple breathing states. It provides a realistic experimental environment for medical devices related to pulmonary interventional treatment. Since the physiological and physical characteristics of biological lungs are different, the multiple positive pressure ventilation modes possessed by the device of the present invention can achieve adaptive ventilation effects according to different biological lungs and simulate multiple breathing states. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the device of the present invention.

[0030] Figure 2 This is a physical diagram of the device of the present invention.

[0031] Figure 3 This is an exploded view of the air pressure throttle tube.

[0032] Figure 4 Schematic diagram of air flow through a throttle hole.

[0033] Figure 5 Flowchart for the adaptive pressure-regulated volume positive pressure ventilation mode.

[0034] Figure 6 This is a schematic diagram of the host computer interface. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings.

[0036] like Figures 1 to 6 The present invention provides a positive pressure ventilation device simulating human biological lung, comprising a biological simulated lung 1, a three-way joint 2, an air pressure throttling tube 3, a blower 4, a vacuum pump 5, a pressure sensor 6, a controller 7, a host computer 8 and a drive board 9. The three interfaces of the three-way joint 2 are respectively connected to the biological simulated lung 1, the air pressure throttling tube 3 and the air suction port of the vacuum pump 5. The air outlet of the blower 4 is connected to the air pressure throttling tube 3. A plurality of throttling holes 31 are arranged in the air pressure throttling tube 3. All the throttling holes are located on the same circumferential surface. Two detection tubes 32 are led out from the air pressure throttling tube 3. The air inlets of the two detection tubes 32 are located on both sides of the upstream and downstream of the throttling holes. A pressure sensor 6 is arranged at the air outlet of each detection tube. The pressure sensor 6 is connected to the controller 7. The drive board 9 is connected to the blower 4 and the controller 7. The controller is connected to the host computer 8.

[0037] The biological simulated lung 1 adopts the biological lung of Changzhou Langhe Medical Instrument Co., Ltd. (the biological simulated lung is made of pig lung by special lavage method). The specific object is as follows Figure 2 A disposable tracheal cannula 11 is inserted into the biological simulated lung 1, and the tracheal cannula 11 is connected to a three-way connector 2, and two bellows 21 are connected to the three-way connector 2, and the two bellows 21 are respectively connected to the air pressure throttling tube 3 and the vacuum pump 5.

[0038] The air pressure throttle tube 3 is a detachable structure, with a total length of 225mm, including a connecting tube 32 and a throttle tube 33. The inner cavity of the throttle tube 33 is provided with a throttle plate with a thickness of 6mm and a diameter of 22mm. The throttle plate is provided with 6 throttle holes 31 with a diameter of 3mm and 1 diameter of 6mm. Two connecting tubes 32 are threadedly connected to both sides of the throttle tube 33. A connector 34 for connecting to the detection tube 32 is provided on each connecting tube 32. The length of the connector 34 is 6mm, the outer diameter is 3mm, and the inner diameter is 1mm. The two connectors 34 are 9mm away from the throttle plate and are used to measure the air pressure value and the air pressure difference value.

[0039] The following further describes the process of simulating positive pressure ventilation of human biological lungs by the device.

[0040] The air pressure value and air flow rate value are preset in the host computer. In the set ventilation mode, the blower and the vacuum pump are set to open and close alternately to achieve simulated breathing of the biological simulated lung. The end of each working time of the vacuum pump is a simulated breathing cycle of the biological simulated lung.

[0041] The present invention sets two ventilation modes, corresponding to the controlled air pressure positive pressure ventilation mode and the adaptive pressure regulation volume positive pressure ventilation mode. The two modes are selected in the host computer and then sent to the controller through the RS485 serial port to adopt different control strategies.

[0042] The specific workflows of the two modes are as follows:

[0043] Controlled Airway Pressure (CPAP) Mode:

[0044] The actual air pressure value of the air pressure throttling tube 3 is collected in real time through the pressure sensor 6 on the detection tube 32 downstream of the throttle hole 31, and the actual air pressure value is transmitted to the controller 7. The air pressure value preset on the host computer is transmitted to the controller 7. The actual air pressure value and the preset air pressure value form an incremental control signal through the incremental PID control algorithm in the controller 7. The incremental control signal is sent to the drive board 9 connected to the blower 4. The blower speed is adjusted by the blower drive board 9 until the actual air pressure value collected in real time is equal to the preset air pressure value. When the actual air pressure value is equal to the preset air pressure value, the vacuum pump starts working. When the vacuum pump reaches the set working time, it is a simulated breathing cycle. The blower starts the next simulated breathing cycle by controlling the air pressure positive pressure ventilation mode again. The waveform of the actual air pressure value is displayed in real time in the host computer.

[0045] This mode of simulation has good real-time performance, can adjust parameters online in real time, and has accurate measurement and good simulation effect.

[0046] Adaptive pressure-regulated volume positive pressure ventilation mode:

[0047] The pressure sensor 6 on the upstream and downstream detection tubes 32 of the throttle hole 31 collects the actual pressure difference formed by the air flow passing through the throttle hole 31, and the pressure difference is converted into an actual airflow value. The actual airflow value is compared with the preset airflow value in the host computer. If the actual airflow value is not equal to the preset airflow value, the speed of the blower is increased or decreased in the next simulated breathing cycle, and then the air pressure value is increased or decreased, thereby forming an adaptive feedback control ventilation mechanism. The opening and closing of the vacuum pump in each simulated breathing cycle is achieved by setting the opening and closing time frequency of the vacuum pump, and the waveform of the actual air pressure value is displayed in real time in the host computer.

[0048] The above converts the pressure difference into the actual airflow value, and the specific function is:

[0049]

[0050] In the formula, β 2 is the diameter ratio of the air pressure throttle tube;

[0051] β 2 =A2 / A1, A2 is the opening area of ​​the throttle hole, A1 is the cross-sectional area of ​​the throttle pressure throttle pipe;

[0052] d is the opening diameter of the throttle hole; ρ is the air density; ε is the expansion coefficient, which is 1 here;

[0053] Δp is the actual pressure difference formed by the airflow passing through the throttle hole;

[0054] The relationship formula between the actual pressure difference and airflow rate formed by the airflow passing through the throttle hole is:

[0055]

[0056] Wherein, C=137.4.

[0057] The converted actual airflow value is compared with the set airflow value. (1) If the actual airflow value is less than the set airflow value, the air pressure output by the blower will be increased in the next simulated breathing cycle. The increased air pressure value is ▲P, and the value of ▲P is related to the set airflow flow value and the actual airflow flow value. The calculation formula is as follows:

[0058]

[0059] At this time, due to the increase in the output pressure of the blower, the actual air flow value also increases accordingly. It is compared with the set air flow value again.

[0060] If the actual air flow value is greater than the set value, the air pressure output by the blower is reduced in the next simulated breathing cycle, and the reduced value is also ▲P, thereby forming an adaptive feedback control ventilation mechanism.

[0061] Adopting the adaptive pressure-adjusted volume positive pressure ventilation mode, under the action of the fuzzy PID control algorithm of this mode, on the one hand, the responsiveness of the device is improved, the adjustment time is shortened, and the actual value in the ventilation circuit reaches the target setting value faster. Under the action of the fuzzy PID control algorithm, the error between the actual value and the target value is controlled below 3%. On the other hand, it avoids the oscillation phenomenon that may occur in the system in a stable state.

[0062] Since the physical characteristics of the simulated biological lungs are different, when changes occur in the form of resistance or compliance in the simulated respiratory mechanics, the pressure in this mode will be adjusted to provide the required airflow value, achieving the purpose of self-adaptation and providing a better simulation environment for medical experiments.

[0063] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the protection scope of the present invention.

Claims

1. A positive pressure ventilation device simulating human biological lungs, characterized in that: The invention comprises a biological simulated lung (1), a three-way joint (2), an air pressure throttling tube (3), a blower (4), a vacuum pump (5), a pressure sensor (6), a controller (7) and a host computer (8). The three interfaces of the three-way joint (2) are respectively connected to the biological simulated lung (1), the air pressure throttling tube (3) and the air suction port of the vacuum pump (5). The air outlet of the blower (4) is connected to the air pressure throttling tube (3). A plurality of throttling holes (31) are arranged in the air pressure throttling tube (3). All the throttling holes are located on the same circumferential surface. Two detection tubes (32) are led out from the air pressure throttling tube (3). The air inlets of the two detection tubes (32) are located on both sides of the upstream and downstream of the throttling holes. A pressure sensor (6) is arranged at the air outlet of each detection tube. The pressure sensor (6) is connected to the controller (7), and the controller is connected to the host computer (8).

2. The positive pressure ventilation device simulating human biological lungs as claimed in claim 1, characterized in that: A disposable tracheal cannula (11) is inserted into the biological simulated lung (1), and the tracheal cannula (11) is connected to a three-way connector (2).

3. The positive pressure ventilation device simulating human biological lungs as claimed in claim 1, characterized in that: The three-way joint (2) is connected to two bellows (21), and the two bellows (21) are respectively connected to the air pressure throttling tube (3) and the vacuum pump (5).

4. The positive pressure ventilation device simulating human biological lungs as claimed in claim 1, characterized in that: The air pressure throttle tube (3) is a detachable structure, comprising a connecting tube (32) and a throttle tube (33), wherein a throttle plate is provided in the inner cavity of the throttle tube (33), and the throttle plate is provided with a plurality of throttle holes (31); two connecting tubes (32) are threadedly connected to both sides of the throttle tube (33), and each connecting tube (32) is provided with a connector (34) for connecting to a detection tube (32).

5. A method for simulating positive pressure ventilation of human lungs based on the device according to any one of claims 1 to 4, characterized in that: The air pressure value and air flow rate value are preset in the host computer. In the set ventilation mode, the blower and the vacuum pump are set to open and close alternately to achieve simulated breathing of the biological simulated lung. The end of each working time of the vacuum pump is a simulated breathing cycle of the biological simulated lung.

6. The method for simulating positive pressure ventilation of human biological lungs as claimed in claim 5, characterized in that: The ventilation mode includes a controlled air pressure positive pressure ventilation mode, and the controlled air pressure positive pressure ventilation mode is: The actual air pressure value of the air pressure throttling tube (3) is collected in real time through the pressure sensor (6) on the detection tube (32) downstream of the throttling hole (31), and the actual air pressure value is transmitted to the controller (7). The air pressure value preset on the host computer is transmitted to the controller (7). The actual air pressure value and the preset air pressure value are formed into an incremental control signal through the incremental PID control algorithm in the controller (7). The incremental control signal is sent to the drive board (9) connected to the blower (4). The blower driving board (9) adjusts the speed of the blower until the actual air pressure value collected in real time is equal to the preset air pressure value. When the actual air pressure value is equal to the preset air pressure value, the vacuum pump starts to work. When the vacuum pump reaches the set working time, it is a simulated breathing cycle. The blower starts the next simulated breathing cycle by controlling the air pressure positive pressure ventilation mode again.

7. The method for simulating positive pressure ventilation of human biological lungs as claimed in claim 5, characterized in that: The ventilation mode also includes an adaptive pressure-regulated volume positive pressure ventilation mode, and the adaptive pressure-regulated volume positive pressure ventilation mode is: The actual air pressure difference formed by the air flow passing through the throttle hole (31) is collected by the pressure sensor (6) on the upstream and downstream detection tubes (32) of the throttle hole (31), and the air pressure difference is converted into an actual air flow value. The actual air flow value is compared with the preset air flow value in the upper computer. If the actual air flow value is not equal to the preset air flow value, the speed of the blower is increased or decreased in the next simulated breathing cycle, and then the air pressure value is increased or decreased, thereby forming an adaptive feedback control ventilation mechanism. The opening and closing of the vacuum pump in each simulated breathing cycle is achieved by setting the opening and closing time frequency of the vacuum pump.

8. The method for simulating positive pressure ventilation of human biological lungs as claimed in claim 7, characterized in that: The pressure difference is converted into an actual airflow value, and the specific function is: In the formula, β 2 is the diameter ratio of the air pressure throttle tube; β 2 =A2 / A1, A2 is the opening area of ​​the throttle hole, A1 is the cross-sectional area of ​​the throttle pressure throttle pipe; d is the opening diameter of the throttle hole; ρ is the air density; ε is the expansion coefficient, which is 1 here; Δp is the actual pressure difference formed by the airflow passing through the throttle hole; The relationship formula between the actual pressure difference and airflow rate formed by the airflow passing through the throttle hole is: Wherein, C=137.

4.

9. The method for simulating positive pressure ventilation of human biological lungs as claimed in claim 5, characterized in that: The host computer displays a waveform diagram of the actual air pressure value in real time.

10. The method for simulating positive pressure ventilation of human biological lungs as claimed in claim 5, characterized in that: The pressure value for increasing or decreasing ▲P is calculated by the following formula:

Images